(NewsNation) — As Gilgo Beach killings suspect Rex Heuermann awaits trial, he is being held in a correctional facility where he has limited space and is kept under constant supervision.

The Suffolk County Sheriff’s Office, led by Sheriff Errol D. Toulon Jr., undersees two correctional facilities on New York’s Long Island where 944 inmates call Riverhead and Yaphank home.

One of those inmates is Rex Heuermann.

The 60-year-old architect is charged with the murders of Melissa Barthelemy, Megan Waterman and Amber Costello and is the prime suspect in the murder of Maureen Brainard-Barnes, all sex workers known as the “Gilgo Four.”

Toulon Jr. gave NewsNation an exclusive, behind-the-scenes view of what life is like behind bars for one of the most notorious serial killing suspects in recent history.

Heuermann’s new home is sixty feet by sixty feet, with a fixed bed, bench, desk and stool.

“You know, this is a typical cell,” Toulon Jr. said. “There’s a toilet, sink, plastic mirror because we don’t want them to have glass. They can easily break that and use that either to harm themselves or harm someone else.”

Heuermann’s cell is no different than any other inmate being held at the Suffolk County correctional facility despite his size. Standing 6 feet, 4 inches and weighing 280 pounds, Heuermann might seem to be cramped in the small space.

“We’re not here to accommodate those that are coming to our custody, because of size or weight or anything like that,” Toulon Jr. said.

When Heuermann first arrived, Toulon Jr. said he would lay on the mattress, looking at the ceiling.

“He was just sleeping,” Toulon Jr. said. “The second time he was looking up at the ceiling, third time he was on his bunk with his back against the wall.”

One thing that isn’t in Heuermann’s cell is anything on the walls.

“We do not allow any pictures on the walls,” Toulon Jr. explained. “Because if someone’s manipulating a wall and trying to cover it with the picture, we don’t authorize it.”

Heuermann is also under 24/7 surveillance.

“We have a correctional officer that’s monitoring his cell every single day. In addition, we have an additional camera in the housing area. Also, we do have medical staff that comes two to three times a day, just to check on him,” Toulon Jr. said.

While under supervision, Heurmann has a list of essential services available to him.

“He’s able to have books, he’s able to go to recreation, religious services, he goes to medical, goes to the law library, goes to rehabilitation, so he’s become a lot more acclimated inside of his housing area,” Toulon Jr. said.

Heuermann has the opportunity to play basketball, do pullups and situps or just pace around the recreational area.

Heuermann is even able to get a haircut, something many noticed during his last court appearance.

“We were able to identify someone meeting our security procedures that could come in and give Mr. Heuermann a haircut because he requested one,” Toulon Jr. said.

Heuermann was allowed to select his own hairstyle.

He is also allowed to get visitors, though no family members have come to see him. He has only received visits from his attorney and one unknown individual.

“It’s not a name that we are willing to divulge,” Toulon Jr. said. “Because that person, their life would be turned upside down. If he or she decided they wanted to come forward and say, ‘I’m the person to visit Rex Heuremann,’ that would be up to them.”

Heuermann is also allowed to make calls but can’t receive them. He has to dial out of a common area where every conversation is recorded.

Meanwhile, investigators with the Suffolk County Anti-Trafficking Initiative are talking with female inmates who worked as escorts to see if they have any information on Heuermann.

“Mr. Heuermann was seeking out sex workers prior to his arrest. So we do know that there are women out there who may have had some potential contact with him,” Toulon Jr. said.

Toulon Jr. told NewsNation they are keeping Heuermann away from other inmates for now for his own protection and safety.

“My goal is to make sure justice is serviced in the courts and not in the jail,” he said.